Bridge construction



Mar. 6,1923,

G. LJNDENTHAL BRIDGE CONSTRUCTION Filed Dec. 2?, 1921 {i am 85 Mom rPatented ar. 6, 1923..

'* e i Q BRIDGE CONSTRUCTION.

Application filed December 27,1921. Serial no. 524,849.

To all whom it may concern:

Be it known that I, GUSTAV LINDENTHAL, a citizen of the United States,residing at Metuchen, in the county of Middlesex and State f New Jersey,have invented certain new and useful Improvements in BridgeConstruction, of which the following is a specification.

My invention relates to girders, and their use in bridge construction.My invention has more especial reference to plate girders provided withopenings-in the web which openings may be either square, oblong orround. These so-called open work girders are known as Vierendeel irdersand are described and shown in the Tatent No. 639,320 issued on December19th, 1899 to Arthur Vierendeel. These girders, however, have been usedheretofore only for loads moving on top f the girder in the longitudinaldirection of the same, the girder being supported at each end on masonryor a metal tower. The object of my present invention is to use such agirder in the construction of metal bridges as a cross-beam so thatloads can move transverse to the girder on top of the same as well asthrough the openings in the web. By using the girders in this manner Ican produce a metal bridge of reat strength having two decks, an uppereck supported by the tops of the cross-wise girders and a lower deckformed on the bottoms of the said openings.

In the drawing illustrating my inventions, Fig. 1 is an elevational viewof an open work girder diagrammatically indicating the use of the samefor a double-deck bridge construction; Fig. 2 shows two cross sectionsthrough such a girder, one section being through a girder having one webandthe other section being through a girder having two webs. Fig. 3 is asimilar view as Fig. 1 showing a girder for a bridge construction ofgreater carrying capacity and the manner of suspending such a girder.

According to Fig. 1, the girder 1 is provided with two oblong openings2, 3 in its web 4. The web, as shown in Fig. 2 can be either single ordouble depending on the strength and carrying capacity of the bridgeconstruction. The girder as illustrated, is arranged cross-wise, and mayeither be suspended at its ends, as shown at 5, on the right in Fig. 1,or it can be connected to a vertical truss, as shown at 6, on the leftin Fig. 1. As indicated in Fig. 1, the tops of these cross-wise girdersform the support for the upper deck 7 of the bridge, whereas the bottomsof the openings 8 form the support. for the lower deck 8, the girders,as shown, supporting longitudinal beams or girders 9 for carrying tracks(lower deck) or aroadway (upper deck). Tracks, of course, may beprovided both on the lower and the upper deck.

shown in Fig. 1, having four openings, two oblong openings 10, 11 in themiddle portion of the web and two square openings 12, 13, one" ateachend. This girder is shown suspended at it and 15, the top of thegirder supporting a roadway and the bottom of,

the openin s each supporting a track. Longrtudinad girders 9 as in Fig.1 are provided on the cross-wise girders to carry the tracks roadway.

It will be readil seen that this. use of open work girders or a bridgeconstruction with an upper and lower deck formed bying bending stresseswhich with this form of girder when used for a double deck bridge aresmaller than where two separate. girders of smaller depth are used, i.e. one girder for the upper deck and another girder for the lower deck.Moreover, the use. of such open work girders will result in economy oflabor and time.

I claim as my invention.

' 1. In bridge construction with two decks a deep metal girder having anumber of wide openings in the web, and means for supporting the saidgirder at right angles to the bridge, the top of the'girder supportingthe upper deck andv the bottom of the openings supporting the lower deckof the bridge.

2. In bridge construction with two decks a deep metal girder having anumber of wide 85 I Fig. 3, shows a 'wider girder than that i openingsin the Web, means for supporting the said girder at right angles to thebridge, longitudinal been 1s supported by the said girder, and trackscarried by said beams.

3. In bridge construction with two decks a deep metal girder having anumber of Wide openings in the WBb,II1ElDS for supporting the saidgirder transverse to the bridge the top of the girder supporting theupper deck and the bottom of the said openings 10 supporting the lowerdeck, and longitudinal beams supported on said girder for carrying loadsmoving transversely to the said girders.

In testimony whereof I affix my signature. 15

GUSTAV 'LINDENTHAL.

